Suppressive and curative antiplasmodial properties of Nauclea latifolia root extract and fractions against erythrocytic stage of mice-infective chloroquine-sensitive Plasmodium berghei NK-65

Background: Malaria remains a devastating disease, particularly in the tropics, where it is the highest killer of pregnant women and children under the age of 5 years. Significant efforts and resources have been vested in malaria control and eradication programmes, but the unavailability of malaria vaccine and the emergence of resistance of malaria parasite to existing antimalarial drugs have continued to hamper attempts at controlling or eradicating the disease. This warrants the development of new antimalarial drugs. Nauclea latifolia root is widely applied for malaria treatment in Nigeria. Aim: This study investigated the antimalarial property of N. latifolia roots. Setting: N. latifolia roots were collected from Ikwuano, Umuahia, Abia State, Nigeria. Methods: To extract the bioactive constituents, an aqueous infusion of the plant was prepared and fractionated by solvent-solvent extraction with n -hexane, ethyl acetate and butanol, respectively. Antimalarial property was evaluated using suppressive and curative assays in mice infected with chloroquine-sensitive Plasmodium berghei NK-65 strain. Results: The extract and fractions produced significant suppressive and curative antiplasmodial activities ( p < 0.05). The aqueous extract and n -hexane and butanol fractions gave 85.22%, 84.52% and 91.32% chemosuppression, respectively, which were comparable to that of chloroquine used as positive control. The extract and fractions gave considerable curative effects in the range 52.23% – 77.00%. Conclusion: These findings indicate that N. latifolia roots possess antimalarial property and reflect its ethnomedicinal use for malaria treatment. Thus, N. latifolia roots may be exploited for development of herbal formulations and isolation of novel bioactive compounds for malaria treatment.